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Biogeochemistry

Centers, Projects & Initiatives

Microbial oceanographers Andy Juhl and Ajit Subramaniam are working with organic geochemist Beizhan Yan and physical oceanographer Andreas Thurnherr to understand the composition of the hydrocarbons, their transport, and impact on the microbial ecosystem of the Gulf of Mexico.

This page contains information on the research activities in R. Sambrotto's Lab. at Lamont-Doherty. Its covers the people involved and the analytical work we do on the biogeochemistry of oceans and estuaries. It includes the analytical capabilities available to outside users as well as information and protocols for people working in the lab.

My primary research interest is in reconstructing ancient terrestrial ecosystems using light stable isotopes (H, C, N, & O) and other geochemical tools. I also employ these tools to study modern ecosystems in East Africa.

News items

Human actions are changing the oceans’ chemistry. To predict how marine ecosystems are going to respond to these changes, we need to understand how marine biology and ocean chemistry interact today. This week, biologist and geochemists from around the world gathered at Lamont to find new ways to combine their expertise to analyze GEOTRACES data on trace elements and nutrients.

Over the past half-million years, the equatorial Pacific Ocean has seen five spikes in the amount of iron-laden dust blown in from the continents. In theory, those bursts should have turbo-charged the growth of the ocean’s carbon-capturing algae­ – algae need iron to grow – but a new study led by Lamont Gisela Winckler shows that the excess iron had little to no effect. The results are important today, because as groups search for ways to combat climate change, some are exploring fertilizing the oceans with iron as a solution.

A new study questions the popular notion that 10th-century Norse people were able to colonize Greenland because of a period of unusually warm weather. Based upon signs left by old glaciers, researchers say the climate was already cold when the Norse arrived—and that climate thus probably played little role in their mysterious demise some 400 years later. On a larger scale, the study adds to building evidence that the so-called Medieval Warm Period, when Europe enjoyed exceptionally clement weather, did not necessarily extend to other parts of the world.

Nicolás Young was just named a winner of a 2015 Blavatnik Award for his work measuring ice sheets in changing climates of the past and their contribution to sea level rise. His new projects are taking glacier tracking to the next level.

A growing "dead zone" in the middle of the Arabian Sea has allowed plankton uniquely suited to low-oxygen water to take over the base of the food chain. Their rise to dominance over the last decade could be disastrous for the predator fish that sustain 120 million people living on the sea’s edge.

O. Roger Anderson is a microbiologist at Lamont-Doherty Earth Observatory who studies bacteria, amoebas, fungi and other microorganisms. Lately he has been thinking about how tiny organisms that inhabit the vast northern tundra regions could contribute to changing climate, since, like humans, they breathe in oxygen and breathe out carbon dioxide.

The oceans play a key role in regulating climate, absorbing more than a quarter of the carbon dioxide that humans put into the air. Now, the first year-by-year accounting of this mechanism during the industrial era suggests the oceans are struggling to keep up with rising emissions...